[Wnt5a modulates vincristine resistance through PI3K/Akt/GSK3ß signaling pathway in human ovarian carcinoma SKOV3/VCR cells].

The aim of this study was to investigate the effect of Wnt5a on the vincristine (VCR) resistance in human ovarian carcinoma SKOV3 cells and its possible mechanism. The drug-resistant SKOV3/VCR cells were established by stepwise exposure to VCR, and then the SKOV3/VCR cells were stably transfected with specific shRNA interference plasmid vector targeting for Wnt5a. The mRNA expression level of Wnt5a was measured by RT-PCR. CCK-8 assay was used to detect the cell viability of SKOV3/VCR cells. The apoptosis was analyzed by flow cytometry. The protein expression levels of Wnt5a, MDR1, Survivin, ß-catenin, Akt, p-Akt(S473), GSK3ß and p-GSK3ß(Ser9) were detected by Western blot. The result showed that SKOV3/VCR cells had significantly higher protein expression levels of Wnt5a, MDR1, Survivin and ß-catenin, phosphorylation levels of Akt and GSK3ß, and mRNA expression level of Wnt5a, compared with SKOV3 cells (P < 0.05). WNT5A gene silencing significantly increased the sensitivity of SKOV3/VCR cells to VCR, the IC50 of VCR being decreased from 38.412 to 9.283 mg/L (P < 0.05), synergistically enhanced VCR-induced apoptosis of SKOV3/VCR cells (P < 0.05), down-regulated the protein expression levels of MDR1, ß-catenin and Survivin (P < 0.05), and inhibited phosphorylation of Akt and GSK3ß (P < 0.05). Meanwhile, LY294002 (PI3K inhibitor) decreased the protein expression levels of MDR1, ß-catenin and Survivin, as well as the phosphorylation levels of Akt and GSK3ß in SKOV3/VCR cells (P < 0.05). These results suggest that WNT5A gene silencing reverses VCR resistance in SKOV3/VCR cells possibly through blocking the PI3K/Akt/GSK3ß/ß-catenin signaling pathway, and thus down-regulating the protein expression levels of MDR1 and Survivin.

[A review of recent ten-year study on alpha-asarone].

This article is brief review of study on alpha-asarone after 1996. The summary mainly includes the dosage forms, pharmacokinetics, bioavailability, pharmacological effects, toxicology and clinical uses during the past ten years.

Transfection of primary chondrocytes using chitosan-pEGFP nanoparticles.

Chitosan-pEGFP nanoparticles were synthesized through the complex coacervation of the cationic polymer with pEGFP, in order to examine the potential of chitosan as a non-viral gene delivery vector to transfer exogenous gene into primary chondrocytes for the treatment of joint diseases. The nanoparticles were prepared at an N/P ratio of 3.8 and showed a spherical or irregular shape. The mean particle size and zeta potential of the nanoparticles freshly prepared with chitosan of different molecular weight were in the range of 100-300 nm and varied from +1 to +23 mV, respectively. Both the particle size and the zeta potential altered in DMEM of different pH. The transfection of primary chondrocytes was performed in different conditions by varying pH of transfection medium, molecular weight of chitosan and different plasmid dosage. Analysis of FACS demonstrated that the transfection efficiency could reach a much high level and the percentage of positive cells could exceed 50% in certain condition. These results suggest that chitosan-DNA nanoparticles have favorable characteristics for non-viral gene delivery to primary chondrocytes, and have the potential to deliver therapeutic genes directly into joint.

[Influence of seven absorption enhancers on nasal mucosa--assessment of toxicity].

OBJECTIVE: To study the influence of seven different absorption enhancers on nasal mucosa. METHODS: By testing last time of ciliary movement, velocity of ciliary movement, ciliary structural and specific cellular changes of nasal mucosa the influence of seven different absorption enhancers on nasal mucosa. RESULTS: The effect on lasting time of ciliary movement was 1%SDS>1%SDC>1%Brij35>5%Tween80>0.1%EDTA>5%HP-beta-CD>1%lecithin the effect on velocity of ciliary movement 1%Brij35>1%SDC>1%SDS>0.1%EDTA>1%lecithin>5%Tween80>5%HP-beta-CD,and the effect on ciliary structural and specific cellular changes of nasal mucosa 1%SDS approximately 1%SDC approximately 1%Brij35>5%Tween80>0.1%EDTA approximately 5% HP-beta-CD approximately 1%lecithin. CONCLUSION: The three methods have good correlation.

[Preparation and properties of 5-fluorouracil-loaded chitosan microspheres for the intranasal administration].

OBJECTIVE: To study the preparation technique and release characteristic of 5-fluorouracil loaded chitosan microspheres for the intranasal administration. METHODS: Using the liquid paraffin as the oil phase,and span-80 as the emuifier; 5-fluorouracil-loaded chitosan microspheres were achieved by emulsion-chemical crosslink technique. The orthogonal experimental design was applied to optimize the preparation procedure. Dynamic dialysis method was used to determine the releasing characteristic of microspheres in vitro and it influencing factors. Swelling behavior was expressed by swelling ratio. The degree of mucoadhesion was investigated by determining the mucociliary transport rate(MTR) of the microparticle across a frog palate. RESULTS: Microspheres with a good shape and narrow size distribution were prepared. The average diameter was (43+/-4) microm. The drug loading was 38.5%+/-1.0%. The entrapment efficiency was 79.0%+/-1.8%. The drug release profile in vitro could be described by Higuichi equation Q=0.1035t(1/2)+0.0284 (r=0.9965). Chitosan had good mucoadhesive property and caused a significant reduction in MTR(P<0.01). CONCLUSION: The optimized preparation technique is stable and has a high entrapment efficiency. So it could be used to prepare 5-fluorouracil-loaded chitosan microspheres for the intranasal administration. Chitosan is a good material for nasal preparation and has prospective development in the pharmaceutical field.